Typical workpiece assembly machines move parts clamped to pallets around a continuous loop past a variety of work and assembly stations and frequently are of the stop and go type wherein an operator releases a dog, which has been holding the pallet in indexed position while he is working on the part, when he is finished working on the workpiece. Such systems use considerable time, and one of the prime objects of the present invention is to provide a system wherein a portion of the length of the conveyor line, at least, can move continuously past a number of stations while assembly operations are being performed on the slowly moving workpieces.
The system which has been proposed permits an assembler at a work station to manually hold back a pallet for a period of time in order to complete an assembly operation that was inadvertently delayed, while at the same time saving considerable time over the stop and go method. The system operates such that, upon the operator's releasing such a pallet, the pallet again rapidly respaces itself with relation to the pallet immediately ahead and continues on to the next operator.
Another important advantage of the present system from a time and motion standpoint, is the fact that it tends to "pace" the operators at the various stations along the length of the section in which manual and automatic operations are being performed at various stations while the pallets are moving.